Step down transformer and Vintage American Clock Radio? - UK Vintage Radio Repair and Restoration Discussion Forum

Ryan_1993 · 17th Apr 2016, 7:31 am

Hi all,

I'm in the process of adding a few more pieces to my vintage room and I really like the style of the General Electric Alarm Clock Radios from the 1950s.

My dilemma is if I get a step down transformer is it going to work properly? I have a feeling the timing for the clock will be done by the electrical frequency. Which in the United Kingdom is 50hz but in the USA is 60HZ, so I'm thinking there maybe a few issues. It's also a valve set, would there be any problems about this being run off a Stepdown transformer?

For anyone curious here's a picture of the item.

Kind regards,

Ryan

TonyDuell · 17th Apr 2016, 7:47 am

I am pretty sure the clock will use a synchronous motor and thus it is dependant on mains frequency. It will run slow on 50Hz.

The radio side is probably an 'All American 5' type design with a series heater chain and live chassis. It will work on 50Hz. There might be a bit more hum but nothing more.

There is at least one company that sells a inverter type thing to run 60Hz clocks in the UK or 50Hz clocks in the USA. I doubt it would have the power to run the radio though. You might be able to rewire the clock radio, bringing the clock motor connections out separately, so that you can run the clock off the inverter and the radio off a normal step-down transformer.

robin0577 · 18th Apr 2016, 8:48 pm

There's a chap called Mark Lines in Milton Keynes who's helped me with an american clock frequency converter in the past, this is his website... http://www.electric-clocks.co.uk/index.html

dseymo1 · 18th Apr 2016, 9:23 pm

Nice little project - a 60Hz low-power inverter.
The various outboard PSUs for turntables would provide some design tips.

Herald1360 · 19th Apr 2016, 12:39 pm

For best accuracy, start by multiplying 50Hz by 6, then divide by 5. Maintains the lock to mains frequency which on average is very accurate.

Mike. Watterson · 23rd Apr 2016, 7:54 pm

600Hz VCO divide by 12 for 50Hz lock, for 10 for 60Hz (maybe 9,600 Hz and an extra divide by 16 is better)
Or 12V DC design and a crystal (but a 32768 Watch crystal isn't much use!)

17th Apr 2016, 7:31 am	#1
Ryan_1993 Hexode Join Date: Sep 2012 Location: Yorkshire, UK. Posts: 329	Step down transformer and Vintage American Clock Radio? Hi all, I'm in the process of adding a few more pieces to my vintage room and I really like the style of the General Electric Alarm Clock Radios from the 1950s. My dilemma is if I get a step down transformer is it going to work properly? I have a feeling the timing for the clock will be done by the electrical frequency. Which in the United Kingdom is 50hz but in the USA is 60HZ, so I'm thinking there maybe a few issues. It's also a valve set, would there be any problems about this being run off a Stepdown transformer? For anyone curious here's a picture of the item. Kind regards, Ryan Attached Thumbnails

17th Apr 2016, 7:47 am	#2
TonyDuell Dekatron Join Date: Jun 2015 Location: Biggin Hill, London, UK. Posts: 5,213	Re: Step down transformer and Vintage American Clock Radio? I am pretty sure the clock will use a synchronous motor and thus it is dependant on mains frequency. It will run slow on 50Hz. The radio side is probably an 'All American 5' type design with a series heater chain and live chassis. It will work on 50Hz. There might be a bit more hum but nothing more. There is at least one company that sells a inverter type thing to run 60Hz clocks in the UK or 50Hz clocks in the USA. I doubt it would have the power to run the radio though. You might be able to rewire the clock radio, bringing the clock motor connections out separately, so that you can run the clock off the inverter and the radio off a normal step-down transformer.

18th Apr 2016, 8:48 pm	#3
robin0577 Pentode Join Date: Oct 2010 Location: London, UK. Posts: 139	Re: Step down transformer and Vintage American Clock Radio? There's a chap called Mark Lines in Milton Keynes who's helped me with an american clock frequency converter in the past, this is his website... http://www.electric-clocks.co.uk/index.html __________________ "Broken we can fix, cr*p is a design issue"

18th Apr 2016, 9:23 pm	#4
dseymo1 Retired Dormant Member Join Date: Dec 2007 Location: Shropshire, UK. Posts: 3,051	Re: Step down transformer and Vintage American Clock Radio? Nice little project - a 60Hz low-power inverter. The various outboard PSUs for turntables would provide some design tips.

19th Apr 2016, 12:39 pm	#5
Herald1360 Dekatron Join Date: Feb 2007 Location: Leominster, Herefordshire, UK. Posts: 16,535	Re: Step down transformer and Vintage American Clock Radio? For best accuracy, start by multiplying 50Hz by 6, then divide by 5. Maintains the lock to mains frequency which on average is very accurate. __________________ ....__________ ....\|____\|\|__\|__\_____ .=.\| _---\__\|__\|_---_\|. .........O..Chris....O

23rd Apr 2016, 7:54 pm	#6
Mike. Watterson Heptode Join Date: Dec 2014 Location: Limerick, Ireland. Posts: 901	Re: Step down transformer and Vintage American Clock Radio? 600Hz VCO divide by 12 for 50Hz lock, for 10 for 60Hz (maybe 9,600 Hz and an extra divide by 16 is better) Or 12V DC design and a crystal (but a 32768 Watch crystal isn't much use!)